Health Media Ltd

Although previous research has suggested DBT is a promising treatment for borderline personality disorder, many of these studies have been preliminary in nature and uncontrolled.

Dr Roel Verheul from the University of Amsterdam - in collaboration with colleagues from the Amsterdam Institute for Addiction Research and Erasmus University in Rotterdam - randomly assigned 58 women with borderline personality disorder to either 12 months of DBT or usual treatment.

DBT consisted of individual, cognitive-behavioural therapy sessions, combined with group therapy sessions on skills training. The treatment was designed to improve motivation and teach skills for self-acceptance and the acceptance of others.

Reporting in the British Journal of Psychiatry, the team found that 63 per cent of patients who received DBT completed the one-year treatment with the same therapist, compared with only 23 per cent of the patients who received control therapy.

Compared with usual treatment, 12 months of DBT resulted in greater reductions in self-mutilating and self-damaging impulsive behaviours, particularly among women with a history of frequent self-mutilation.

Because there is little evidence that DBT is effective for other core features of borderline personality disorder - such as interpersonal instability, chronic feelings of emptiness and boredom and identity disturbance - the team suggest that DBT may be a treatment for patients with severe, life-threatening impulse control disorders, rather than for borderline personality disorder itself.

"Knowledge about the specific mechanisms that make dialectical behaviour therapy work might enable therapists to better direct the focus in treatment," they conclude.